chore: print actual message for TestBrowserContextCDPSession.shouldDe… (#1701)

Author: yury-s

playwright/src/test/java/com/microsoft/playwright/TestBrowserContextCDPSession.java

@@ -132,7 +132,7 @@ void shouldDetachWhenPageCloses() {
     page.close();
 
     PlaywrightException exception = assertThrows(PlaywrightException.class, session::detach);
-    assertTrue(exception.getMessage().contains("Target page, context or browser has been closed"));
+    assertTrue(exception.getMessage().contains("Target page, context or browser has been closed"), exception.getMessage());
     context.close();
   }